75 
but the author supposes it may originate in the decomposition 
of that portion of the indigo blue which yields anthranilic 
acid. 
Hence it appears that all these products, except anthranilic 
acid, are formed by a very simple process which consists 
merely in indigo blue taking up alcohol and acetic acid in 
various proportions and forming compound bodies in which 
none of the constituents, as such, can be detected. It is, 
therefore, not a process of decomposition, but a synthetical 
process, a building up of complex bodies from others of a 
simpler constitution. This is proved by the fact of water 
being given up during the process, whereas in all cases in 
which complex organic substances are decomposed into 
simpler ones, water is absorbed. Regarding the real con- 
stitution of these bodies, the author hazards no speculations. 
It might be supposed that they belonged to the class of 
conjugated compounds, of which organic chemistry furnishes 
us with so many examples, and that by decomposition we 
should be able to obtain from them some of the simpler 
bodies which are known to have entered into their composition, 
but the author’s experiments, as far as they have gone, do 
not countenance this view. He was unable to obtain from 
any one of them, either indigo blue, alcohol, or acetic acid. 
The occasional disappearance of the indigo blue in the 
woad vat in consequence of mismanagement now admits, the 
author thinks, of any easy explanation. By the fermentation 
of the sugar contained in the madder employed, alcohol is 
formed, which in its turn may yield some acetic acid and 
